Answer:
P = 58.52 atm
Explanation:
Given data:
Mass of sample = 32.0 g
Pressure of sample = ?
Volume of gas = 850 cm³
Temperature of gas = 30°C
Solution:
Number of moles of gas:
Number of moles = mass/molar mass
Number of moles = 32.0 g/ 16 g/mol
Number of moles = 2 mol
Pressure of gas:
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
Now we will convert the temperature.
30+273 = 303 K
850 cm³ × 1L /1000 cm³ = 0.85 L
by putting values,
P× 0.85 L = 2 mol × 0.0821 atm.L/ mol.K × 303 K
P = 49.75 atm.L/ 0.85 L
P = 58.52 atm
Answer:
B They move because of the convection currents in the mantle.
The correct answer is C. As heated material gets closer to the surface, it begins to cool.
Explanation:
Convection currents involve the flow and movement of particles in gases or liquids due to changes in temperature and density. This occurs on the Earth's mantle, which is partially liquid and it is located between the core (center of Earth) and the crust composed of plates.
In this way, molten material that is near the core heats and rises as it is less dense, but once it reaches the crust it cools, and after some time it sinks again as the magma increases its density. This cycle is constant and causes the movement of the plates in the crust, that might move apart or toward other plates. According to this, the only accurate statement is "As heated material gets closer to the surface, it begins to cool".
